CHEMOSENSORY RECOGNITION OF NORTHERN PIKE (ESOX-LUCIUS) BY BROOK STICKLEBACK (CULAEA INCONSTANS) - POPULATION DIFFERENCES AND THE INFLUENCE OF PREDATOR DIET

Chemical recognition of familiar or unfamiliar predators may allow prey to detect predators under conditions in which vision is of limited utility. In laboratory tests, brook stickleback (Culaea inconstans) from a pike-allopatric population responded to chemical stimuli from northern pike (Esox lucius) with an appropriate anti-predator behaviour (decreased activity) only when the stimulus was obtained from pike that had eaten conspecific stickleback. In contrast, stickleback from a pike-sympatric population exhibited a fright response to chemical stimuli from pike that had eaten only heterospecific fish prey. Our study is the first to demonstrate chemosensory recognition of predators by a stickleback (family Gasterosteidae). Our results further indicate that predator diet influences chemosensory recognition of unfamiliar predators and that individuals from a predator-sympatric population can recognize predators even when the predator's recent diet has not included conspecific fish prey.